Resin made container

ABSTRACT

A resin made container includes a spout portion to/from which a cap can be attached/detached, a shoulder portion continuous with the spout portion, a body portion continuous with the shoulder portion and a bottom portion continuous with the body portion and disposed at a lowermost portion of the bottle. At a lateral wall lower end of the bottom portion, there is formed a step which is receded to the inner side along a circumferential direction.

TECHNICAL FIELD

This invention relates to a resin made container such as a PET bottle.

BACKGROUND ART

As conventional resin made containers, there is known, from PatentDocument 1, a PET bottle having a constricted portion and a plurality ofannular grooves, which are provided in a body portion of the bottle.With this PET bottle, even if a certain shock or load is applied theretofrom the vertical direction during e.g. conveyance, such shock or loadwill be absorbed by elastic deformation occurring in the constructedportion or the annular grooves, so buckling deformation will not occureasily.

BACKGROUND ART DOCUMENT Patent Document

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2008-13180

SUMMARY OF INVENTION Problem to be Solved by Invention

However, with the conventional PET bottle, with provision of theconstricted portion or the plurality of annular grooves, their unevenappearance can impair the aesthetic feature. Thus, there remains roomfor improvement. Accordingly, an object of the invention is to improvethe buckling resistance of a resin made container without impairing itsaesthetic feature.

Solution

For accomplishing the above-noted object, according to a firstcharacterizing feature of a resin made container relating to the presentinvention, the resin made container includes a spout portion to/fromwhich a cap can be attached/detached, a shoulder portion continuous withthe spout portion, a body portion continuous with the shoulder portionand a bottom portion continuous with the body portion and disposed at alowermost portion of the bottle;

wherein at a lateral wall lower end of the bottom portion, there isformed a step which is receded to the inner side along a circumferentialdirection.

According to a further characterizing feature of the resin made bottleof the invention, the step has a vertical cross sectional shape which isformed of a first curved portion which protrudes to the outer side ofthe container, a second curved portion which protrudes to the inner sideof the container, and a third curved portion which protrudes to theouter side of the container, the first through third curved portionsbeing formed continuous in this order from the upper side.

According to a still further characterizing feature of the resin madecontainer of the invention, the second curved portion has a curvatureradius smaller than a curvature radius of the first curved portion.

According to a still further characterizing feature of the resin madecontainer of the invention, the curvature radii respectively of thefirst curved portion, the second curved portion and the third curvedportion are all smaller than or equal to 5 mm.

According to a still further characterizing feature of the resin madecontainer of the invention, the step has a height smaller than or equalto 4 mm.

According to a still further characterizing feature of the resin madecontainer of the present invention, a diameter decrease ratio of amaximum outer diameter of a bottom face of the bottom portion relativeto a maximum outer diameter of the lateral wall of the bottom portionranges from 60% to 90%.

According to a still her characterizing feature of the resin madecontainer of the invention, a bottom wall of the bottle portion has areceded portion which is receded to the inner side of the container.

Effect of the Invention

With the inventive feature of a step receded to the inner side along acircumferential direction being formed at a lateral wall lower end ofthe bottom portion, this step functions like a spring, thus improvingthe buckling resistance of the container. Therefore, as there is no needto provide a constricted portion or a plurality of annular groovesconventionally provided, the aesthetic feature of the container is notimpaired and also the buckling deformation will occur less unlikely.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a resin made container,

FIG. 2 is a side view of the resin made container,

FIG. 3 is a vertical sectional view of the resin made container takenalong a line III-III in FIG. 2,

FIG. 4 is an enlarged view of a depressurisation absorbing portion,

FIG. 5 is a vertical sectional view of a bottom portion of the resinmade container, and

FIG. 6 is an enlarged view showing vicinity of a connecting portionbetween a shoulder portion and a body portion of a resin made containeraccording to a further embodiment.

MODES OF EMBODYING THE INVENTION Embodiment

Next, as a preferred embodiment of a resin made container relating tothe present invention, there will be explained a plastic bottle 1 to becharged with liquid such as beverage, with reference to the accompanyingdrawings.

Firstly, various kinds of terms to be used in this detailed descriptionwill be defined as follows.

As used in this detailed description, a term “vertical direction” meansa direction of a center axis X-X of a plastic bottle 1 shown in FIG. 1(to be referred to simply as “bottle 1” hereinafter). In particular, inFIGS. 1-3, a term: upper side, refers to the upper end side in thedrawings and a term: lower side refers to the lower end side of thedrawings.

A term “lateral direction” or “horizontal direction” means the directionperpendicular to the center axis X-X direction.

A term “circumferential direction” means a direction along the contourof the horizontal cross sectional shape.

A term “radial direction” means the radial direction of a circle whenthe the center axis X-X is taken as the center of such circle.

A term “height” means a length along the center axis X-X direction.

A term “depth” means a length along the radial direction.

A term “horizontal cross sectional shape” means a cross sectional shapeof the bottle 1 in a plane (horizontal cross section) perpendicular tothe center axis X-X.

A term “vertical sectional shape” means a cross sectional shape of thebottle 1 in a plane (vertical cross section) along the center axis X-X.

As shown in FIGS. 1 through 3, the bottle 1 relating to the instantembodiment includes, from the upper side thereof, a spout portion 2to/from which a cap can be attached/detached, a shoulder portion 3continuous with the spout portion 2, a body portion 4 continuous withthe shoulder portion 3, and a bottom portion 11 continuous with the bodyportion 4 and located at the lowermost portion. Further, the bottle 1relating to the instant embodiment is a cylindrical container having anapproximately circular horizontal cross section.

The bottle 1 can be made of thermoplastic resin such as polyethylene,polypropylene, polyethylene terephthalate, etc. as its principalmaterial, via a conventional molding method such as the biaxialstretching blow molding technique.

The content (liquid) to be charged in the bottle 1 is not particularlylimited. As examples thereof, drinks such as drinking water, tea, juice,coffee, cocoa, soft drink, alcoholic drink, milk-based drink, soup,liquid seasoning such as sauce, soy sauce, etc. can be cited. Further,the content volume of the bottle 1 is also not particularly limited.Depending on the kind of content to be charged therein, it can beappropriately set from a relatively small volume in the order of a fewhundreds of milliliters, to a relatively large volume in the order to afew liters. Incidentally, when the bottle 1 is used as a beveragebottle, it is desired that its content volume ranges from 500 to 550 mL.

(Spout Portion)

The spout portion 2 is a part which is formed of a cylinder having anopened upper end and serves as an inlet for the content. In the outercircumferential face of the spout portion 2, male threads are formed. Sothat, an unillustrated cap may be adapted to be detachably fixedlythreaded thereto, thus allowing repeated sealing and opening.

(Shoulder Portion)

The shoulder portion 3 is a part which is provided with an approximatelyconical shape whose diameter progressively increases from its upper endto the lower side thereof. Advantageously, the vertical cross sectionalshape of the shoulder portion 3 may be a gentle arc which is formed toprotrude to the outer side of the container (e.g. curvature radius=250mm (250R)).

(Body Portion)

The body portion 4 continuously decreases in its diameter from its upperend to the lower side and then continuously increases in its diameterfrom a position approximately at the vertical half of the body portion 4to be continuous with a bottom portion 11. Incidentally, the verticalcross sectional shape of the body portion 4 in the instant embodiment isconstituted of continuation of two arcs having different curvature radiifrom each other. In the instant embodiment, the curvature radius of thearc of the approximately upper half portion of the body portion 4 is setsmaller than the curvature radius of the arc of the approximately lowerhalf portion of the body portion 4. The curvature radius of the arc ofthe approximately upper half portion of the body portion 4 can be e.g.600 mm (600R) and the curvature radius of the arc of the approximatelylower half portion of the body portion 4 can be 1052 mm (1052R), forinstance.

In the body portion 4, there are provided, in the form of recesses, aplurality of depressurization absorbing portions 5 by a predeterminedspacing in the circumferential direction. Incidentally, thedepressurization absorbing portions 5 in the instant embodiment areprovided in the form of recesses distributed in both the upper halfportion and the lower half portion of the body portion 4. On the upperside of each depressurization absorbing portion 5, there is formed atapered region 6 whose diameter progressively decreases and whose depthprogressively decreases toward the upper side. In the instantembodiment, the tapered regions 6 are provided at the upper half portionof the body portion 4.

As shown in FIG. 4, the depressurization absorbing portion 5 iscomprised of a tapered region 6, a constant region 7 having a constantwidth having a lateral width equal to the maximum lateral width of thetapered region 6 and an enlarged region 8 having a width whichprogressively increases from the constant region 7, with the taperedregion 6, the constant region 7 and the enlarged region 8 beingcontinuous with each other from the upper sick in this order. Along thecontour of the depressurization absorbing portion 5, there is formed agroove 9 having a V-shaped cross section, and this groove 9, at theupper end of the depressurization absorbing portion 5, is continuouswith the lateral face of the body portion 4.

Incidentally, though not shown, the above-described depressurizationabsorbing portion 5 may be vertically inverted. In such case, thetapered region 6, the constant region 7 and the enlarged region 8 willbe formed continuous with each other from the lower side in this order;and the groove 9, at the lower end of the depressurization absorbingportion 5, will be formed continuous with the lateral face of the bodyportion 4. Further, the tapered region 6 will be provided at the lowerhalf portion of the body portion 4.

In the depressurization absorbing portion 5, there is formed a recededportion 10 which is receded to the inner side of the container. In theinstant embodiment, such receded portion 10 having a rhombus squarepyramid-like shape is formed over and across a part of the constantregion 7 and a part of the enlarged region 8. However, the shape and thedisposing position of the receded portion 10 are not limited to theabove. Incidentally, in the depressurization absorbing portion 5,instead of the receded portion 10 above, a protruding portion whichprotrudes to the outer side of the container may be formed. In thiscase, similarly to the receded portion 10, such protruding portionhaving a rhombus square pyramid-like shape may be formed over and acrossa part of the constant region 7 and a part of the enlarged region 8.However, the shape and the disposing position of such protruding portionare not limited to the above.

Incidentally, advantageously, a ratio of an area summing up therespective surface areas of the tapered region 6, the constant region 7and the enlarged region 8 relative to the total surface area of thebottle 1 can be set to range from 30% to 45% approximately.

(Connecting Portion between Shoulder Portion and Body Portion)

As shown in FIG. 3, the vertical cross sectional shape of a connectingportion C between the shoulder portion 3 and the body portion 4 isformed like an arc which protrudes (convex) to the outer side of thecontainer. This connecting portion C has a curvature radius ranging from1.5 to 5 mm (1.5R to 5R), more preferably from 1.5 to 3.5 mm (1.5R to3.5R). The shape extending from the lower end portion of the shoulderportion 3 through the connecting portion C to the upper end portion ofthe body portion 4 is curved to protrude toward the lateral outer sideof the container.

(Connecting Portion between Body Portion and Bottom Portion)

As shown in FIGS. 1-3, at the connecting portion between the bodyportion 4 and the bottom portion 11, there is formed a circumferentialgroove 20 which extends along and over the entire circumference. Thiscircumferential groove 20 acts as a reinforcing rib for enhancingreinforcement against a shock or a load applied to the lateral face ofthe bottle 1.

As shown in FIG. 5, in the vertical cross sectional shape of thecircumferential groove 20, an edge arc 21 protruding to the outer sideof the container, a bottom arc 23 protruding to the inner side of thecontainer and an edge arc 22 protruding to the outer side of thecontainer are formed continuous with each other from the upper side inthis order. Advantageously, the curvature radii of the edge arcs 21, 22can be greater than the curvature radius of the bottom arc 23. Forinstance, the curvature radii of the edge arcs 21, 22 can be 2 mm (2R)and the curvature radius of the bottom arc 23 can be 1.5 mm (1.5R).Further, advantageously, the depth of the circumferential groove 20 canrange from 1 to 1.5 mm, for example.

(Bottom Portion)

As shown in FIG. 5, the bottom portion 11 is comprised of a lateral wall12 and a bottom wall 13. At the lower end of the lateral wall 12, thereis formed a step 14 which is receded to the inner side along thecircumferential direction.

The step 14 has a vertical cross sectional shape which is formed of afirst curved portion 15 which protrudes to the outer side of thecontainer, a second curved portion 16 which protrudes to the inner sideof the container, and a third curved portion 17 which protrudes to theouter side of the container, the first through third curved portions 15,16, 17 being formed continuous in this order from the upper side.Advantageously, the curvature radius of the second curved portion 16 canbe smaller than the curvature radius of the first curved portion 15.Also advantageously, the respective curvature radii of the first curvedportion 15, the second curved portion 16 and the third curved portion 17all can be smaller than or equal to 5 mm (5R). For instance,advantageously, the curvature radius of the first curved portion 15 canbe 3 mm (3R), the curvature radius of the second curved portion 16 canbe 1.5 mm (1.5R), and the curvature radius of the third curved portion17 can be 2 mm (2R). Further, advantageously, the height of the step 14can be smaller than or equal to 4 mm.

Moreover, the vertical cross sectional shape of the step 14 is notlimited to the above. Alternatively, between the first curved portion 15and the second curved portion 16 and/or between the second curvedportion 16 and the third curved portion 17, a straight portion(s) may beprovided.

The bottom wail 13 of the bottom portion 11 is comprised of a recededportion 18 which is receded to the inner side of the container and abottom face 19 which comes into contact with a disposing surface whenthe bottle 1 is placed vertically thereon. The vertical cross sectionalshape of the receded portion 18 is a round-dome shape which is recededin the form of step. The bottom face 19 has a ring shape as seen in aplan view and is disposed in the outer circumference of the recededportion 18.

Advantageously, a diameter decrease ratio of a maximum outer diameter T2of the bottom face 19 relative to the maximum outer diameter T1 of thelateral wall 12 of the bottom portion 11 can range from 60% to 90%.

Further Embodiment

The shape extending from the lower end portion of the shoulder portion 3across the connecting portion C to the upper end of the body portion 4can be a shape which has a greater degree of protrusion to the lateralouter side of the container, as shown in FIG. 6, for instance. In thisembodiment, an arc 24 protruding to the inner side of the container isformed at the upper end portion of the body portion 4 and this arc 24 iscontinuous with the connecting portion C. The curvature radius of thearc 24 is greater than the curvature radius of the connecting portion Cand can range from 10 to 20 mm (10R to 20R), for instance.

INDUSTRIAL APPLICABILITY

The resin made container of the present invention can be used as acontainer in which beverage, seasoning, etc. is charged in a sealedstate.

DESCRIPTION OF SIGNS

1: bottle

2: spout portion

3: shoulder portion

4: body portion

5: depressurization absorbing portion

6: tapered region

7: constant region

8: enlarged region

9: groove having V-shaped cross section

10: receded portion having rhombus square pyramid-like shape

11: bottom portion

12: lateral wall

13: bottom wall

14: step

15: first curved portion

16: second curved portion

17: third curved portion

18: receded portion

19: bottom face

20: circumferential groove

21, 22: edge arcs

23: bottom arc

24: arc relating to further embodiment

T1: maximum outer diameter of lateral wall of bottom portion

T2: maximum outer diameter of bottom face

C: connecting portion between shoulder portion ion and body portion

1. A resin made container including a spout portion to/from which a capcan be attached/detached, a shoulder portion continuous with the spoutportion, a body portion continuous with the shoulder portion and abottom portion continuous with the body portion and disposed at alowermost portion of the bottle; wherein at a lateral wall lower end ofthe bottom portion, there is formed a step which is receded to the innerside along a circumferential direction.
 2. The resin made container ofclaim 1, wherein the step has a vertical cross sectional shape which isformed of a first curved portion which protrudes to the outer side ofthe container, a second curved portion which protrudes to the inner sideof the container, and a third curved portion which protrudes to theouter side of the container, the first through third curved portionsbeing formed continuous in this order from the upper side.
 3. The resinmade container of claim 2, wherein the second curved portion has acurvature radius smaller than a curvature radius of the first curvedportion.
 4. The resin made container of claim 2, wherein the curvatureradii respectively of the first curved portion, the second curvedportion and the third curved portion are all smaller than or equal to 5mm.
 5. The resin made container of claim 1, wherein the step has aheight smaller than or equal to 4 mm.
 6. The resin made container ofclaim 1, wherein a diameter decrease ratio of a maximum outer diameterof a bottom face of the bottom portion relative to a maximum outerdiameter of the lateral wall of the bottom portion ranges from 60% to90%.
 7. The resin made container of claim 6, wherein a bottom wall ofthe bottle portion has a receded portion which is receded to the innerside of the container.